a fight to the finish

a fight, contest, or match which only ends with the complete defeat of one of the parties involved

一决雌雄（或你死我活）的争斗（或竞赛、比赛）

finish someone off

kill, destroy, or comprehensively defeat someone

杀死；歼灭；击溃

finish up

(chiefly Brit)end a period of time or course of action by doing something or being in a particular position

(主英)（以…）告终；最终（成为）

he finished up as one of Britain's greatest architects.

他最终跻身英国最伟大的建筑师行列。